Fractions, decimals and percentages
One number, three ways to write it. Convert between fractions, decimals and percentages, put them in order, and add and subtract fractions and decimals. Read one step, play with it, then tap “I understand this”.
One number, three names
14, 0,25 and 25% are exactly the same amount. A percentage means “out of 100”, and the second place after the comma is also hundredths.
The hundred grid
Shade squares, or choose a well-known fraction.
Percentages make it easy to compare: 17 out of 20 and 42 out of 50 are hard to compare, but 85% and 84% you see at once.
Converting
- Fraction → decimal: make the denominator 10, 100 or 1 000 (multiply top and bottom by the same number), or divide the numerator by the denominator.
- Decimal → percentage: multiply by 100. 0,35 × 100 = 35%.
- Percentage → fraction: write it out of 100 and simplify: 35% = 35100 = 720.
The converter
Choose a denominator and change the numerator.
Know these by heart: 12 = 50%, 14 = 25%, 34 = 75%, 15 = 20%, 110 = 10%, 18 = 12,5%.
Compare and order
To compare a fraction, a decimal and a percentage, first write them all the same way, for example as percentages. Then it is easy.
On the number line
Tap “New set” for four new numbers.
0,7 is bigger than 0,65, even though 0,65 has more digits. Write 0,70 and 0,65: now you can see it.
Adding and subtracting fractions
- First make the denominators the same: find the lowest common denominator (LCM).
- Rewrite each fraction with that denominator.
- Add or subtract the numerators. The denominator stays the same.
- Simplify, and write an improper fraction as a mixed number.
Fraction calculator
Choose + or − and change the two fractions.
Mixed numbers? First add the whole numbers, then the fractions: 112 + 223 = 3 + 36 + 46 = 3 + 76 = 416.
The denominator says how big the pieces are. You can only count pieces of the same size: halves and thirds are like apples and oranges, but sixths and sixths you can add together.
Adding and subtracting decimals
Write the numbers under each other with the commas exactly under each other. Then ones stand under ones, tenths under tenths and hundredths under hundredths.
Commas under each other
Choose + or − and tap “New sum”.
Play: convert and calculate
Fraction, decimal or percent?
Choose the right answer.
Correct: 0Check yourself
- Percent = out of 100. ¼ = 0,25 = 25% and ⅛ = 0,125 = 12,5%.
- Fraction → decimal: make the denominator 10, 100 or 1 000, or divide. Decimal → percent: × 100.
- Compare by making them all the same kind (for example percent).
- Adding fractions: first the same denominator, then just the numerators. Decimals: commas under each other.
Write these points in your maths book. Read them again the night before the test.
Quick questions
Tap an answer. If you get one wrong, read why and go back to that step. You get new questions every time.
You ticked all 6 steps! Now you are ready for the quiz.- Practice sheet for this classQuestions + memo · 2 A4 pagesPractice sheet
- Numbers9 pages · PDFPaperMemo
Ready for more? The Grade 7 quiz on fractions, decimals and percentages gives you new questions every time.
- One step a day is enough. Ten calm minutes work better than an hour the night before the test.
- Look at discounts in shops together: “25% off”. Ask: which fraction is that, and how much do we save on R80?
- Ask your child to tell you the rule in their own words. If they can explain it, they understand it.
- The ticks (“I understand this”) are saved on this device only. We never ask for names or emails.
Follows CAPS for Grade 7 Maths. Always check your teacher’s notes and textbook too.